In particular, goalkeeper David de Gea came in for criticism earlier in the season with some questioning whether the young Spaniard was good enough to be part of a title-winning team.

But the Spain Under-21 international has responded with a series of impressive displays and Ferguson believes the improvement has been timely.

"David's been fantastic," Ferguson told the Daily Star. "His confidence is high and every game he is getting better.

"As I said about Antonio Valencia, if you have got players come into form at this time of the season then it's bonus points.

"David found it difficult at first, made mistakes, but I think we forgive players making mistakes at 21 years of age."

Temperament

Wayne Rooney was one such player who had a question mark over his temperament in his early career.

And Ferguson feels we are now seeing a more rounded player and person as the England forward continues his development.

"You always see a maturity about players when they reach their mid-20s," Ferguson told the Daily Mirror.

"Along with their ability comes the maturity, the thought patterns and the timing - it all comes into their game.

"They are more in control of themselves in terms of what they are capable of doing. Experience helps, of course.

"I don't think Wayne's had many bookings but as a team we haven't had that many compared with others.

"And we've only had one sending off - Jonny Evans (at home to Manchester City)."